BOSTON -- An intergovernmental rival of former Probation Commissioner John O’Brien took the stand in O’Brien’s trial Tuesday, testifying about his suspicions about hiring in the department and the souring of their relationship.

Former Chief Justice of Administration and Management Robert Mulligan could be a key witness, as prosecutors contend O’Brien’s fraudulent certifications on hiring documents submitted to Mulligan allowed the patronage system to continue.

O’Brien and two of his former deputies, Elizabeth Tavares and William Burke, are charged with mail fraud and conspiracy to commit racketeering for allegedly rigging the hiring to send jobs to people with political backing.

Mulligan, who retired as chief of the Trial Court around his 70th birthday last year, could also provide a window for the defense to press its case that Mulligan oversaw a nearly identical system for hiring court officers and was well aware of how personnel decisions were made in the probation department.

On Tuesday, Mulligan recalled his skepticism, prompted by the disparity between the scoring of John Chisholm in an interview at a local court and in the final round where he topped the list.

“He all of a sudden became a probation savant, a probation genius,” said Mulligan, who said the notes of Chisholm’s answers during the final round where “full of detail, thoughtful, well organized” and completely different from notes of his earlier interview, which were “bereft of detail.”

“It didn’t make any sense to me,” Mulligan testified. He said when he spotted former deputy commissioner Patricia Walsh, one of two people who interviewed Chisholm, he questioned her for 45 minutes.

“She said those were his answers,” said Mulligan, who said he “asked her pointedly twice” whether she had been told to treat him as a favored candidate.

Richard O’Neil, a probation official who participated in the local interview that advanced Chisholm as a finalist, previously said Chisholm had been identified as a preferred candidate and he “scored him liberally.”

Chisholm had the backing of former Sen. Jack Hart, according to Hart, and received the job. Mulligan said despite his suspicions, Walsh had told him the process was above board and he had no tangible reasons to block the appointment.

“If I had a glimmer of a reason for not approving it, I would have,” Mulligan said. His questioning of Walsh led to an October 2006 letter from O’Brien who objected to “this unprecedented interrogation.”

Mulligan and O’Brien sparred over budgetary control and personnel, as O’Brien sought to remove judges from the interview process and Mulligan wanted a more objective measure of education and experience to be factored in to the final selection of a candidate, he said.

Page 2 of 3 - A former assistant attorney general and federal prosecutor, Mulligan was appointed to the Boston Municipal Court in 1980 by Gov. Edward King, and rose to become the chief justice of the Superior Court between 1994 and 1999 before heading up the trial court starting in 2003. He is a source of enmity for some.

“I truly believe a lot of this stems from Mulligan’s dislike for Commissioner O’Brien. Dislike may be too moderate of a term; it was contempt, frankly. I don’t know the genesis of Mulligan’s dislike, but it manifested with Mulligan refusing to meet with [O’Brien] for years prior to any of this. He refused to speak with him, and everything was done through written correspondence,” O’Brien loyalist Christopher Bulger told Massachusetts Lawyers Weekly in June. Bulger said, “I think Mulligan will suffer a blistering cross-examination. I can guarantee he does not want to be on the stand.”

The son of longtime Senate President William Bulger, Christopher Bulger was a lawyer for the probation department who now regularly attends the trial to provide O’Brien support. Bulger, the three defendants, Walsh and Francis Wall were identified as potential targets of criminal investigation by independent counsel Paul Ware.

Defense attorneys were on guard throughout the Mulligan’s hours of direct examination Tuesday, raising objections while he answered, which the former head of the trial court either didn’t hear or didn’t acknowledge. At one point prosecutor Fred Wyshak complained, “I think these objections are just disruptive.”

Mulligan said his previously cordial relationship with O’Brien changed when Mulligan became the CJAM (pronounced SEE-JAM).

“I had always known him to be a well met fellow, fairly genial,” Mulligan testified. He said, “After I became CJAM, that changed drastically… It was oppositional almost from the time I took office.”

Mulligan said O’Brien wanted to remove judges from the interviewing process.

“He did not want a judge on the panel, and I rejected that,” Mulligan said. In a 2001 law the commissioner was granted the ability to appoint probation officers, while the chief justice of administration and management retained authority to approve or reject those appointments.

O’Brien bragged in a January 2007 letter that the department’s hiring process “may be the most transparent, accountable and tested process in the public sector.” He said, “I am proud to say that in the vast majority of cases the process has withstood that scrutiny, and it consistently and repeatedly has been found to be fair and to be in compliance with the Contract.”

Mulligan said judges clashed with probation officials over the promotion of an assistant chief probation officer to Fall River District Court. Lucia Ligotti only made the list of finalists after it was expanded from eight candidates to nine candidates, Fall River First Justice Gilbert Nadeau wrote in a March 2005 letter to Mulligan, which prompted the chief judge to ask O’Brien for a written response.

Page 3 of 3 - Mulligan said Donelle Gomes, a 15-year veteran who was the unanimous favorite during the local interview, should have received the promotion over Ligotti, who had worked in a family court for four years. The job was eventually given to Larry Lopes. Ellen Slaney, a former probation official who has said she resisted directives to rig the process, was O’Brien’s representative for the three-person local interview.

Mulligan was 37 years old and a lifelong Boston resident when he was appointed to the bench in 1980. He had donated $1,000 to King in October 1978, according to documents on file at the Governor’s Council.

Mulligan served in the U.S. Army from 1968 to 1971, with the rank of lieutenant, and won four bronze stars in the Vietnam War. He spent two years in the Boston Municipal Court before King nominated him to the Superior Court in 1982.